Hi everybody. I just bought and installed Snow Leopard on my 3 year old MacBook yesterday and today my computer doesn't even want boot. The install went fine and I tested various programs afterward and everything seemed to be running smoothly. After playing around with it I shut it down and installed two 1 gig sticks of Crucial brand RAM as I had just 1 gig before and I heard SL needed at least 1 gig. Turned it back on, and checked "About This Mac" which said it only had 1 gig. So I shut it back down and reinstalled the RAM, making sure to really get the RAM in there securely. After my second attempt my MacBook reported having 2 gigs of RAM and for a while ran well. Then later last night it started completely freezing while using firefox and I would have to crash it and restart it. I would use firefox again for a couple of minutes then it would completely freeze and I would be forced to once again crash it. It did this 3 or 4 times and when I restarted it again, the power light came on, but there was nothing but a black screen and the slight hum of the fan.. no HD spinning noise or disk drive noise as usual, and it did not even open to the welcome screen, just a plain black screen. I tried starting in safe mode but nothing happens and it doesn't even seem to try to be booting up as there are none of the usual noises. I tried starting up with the SL install disk, and it made some promising sounds, but nothing different has happened. Any ideas? Should I try using my old RAM or is it definitely the new OS?